1. Field of the Invention
The present invention relates to a system of electronic reprographics and, more particularly, to a method and apparatus for recovering from faults in an electronic reprographic system.
1. Description of the Related Art
In electronic reprographic printing systems, a complex series of interactions occurs between the software services and objects and the hardware functions to provide the printed or otherwise processed end-product. In such a system, a document or series of documents comprising at least one print job are successively scanned, resulting in image signals which are electronically stored. The signals are later read out successively and transferred to a printer for formation of the images on paper. Such a document can be printed any number of times or processed in any number of ways (e.g., words deleted or added; image magnified or reduced, etc.). If a plurality of documents comprise a job which is being processed, the processing or manipulation of the documents can include deletion of one or more documents, reordering of the documents into a desired order, or addition of a previously or subsequently scanned document or documents. The printing or processing can be relatively synchronous with scanning, or asynchronous after scanning. If asynchronous, a time interval exists between scanning and printing or processing. The system can then accumulate a number of scanned jobs in the system memory for subsequent processing or printing. The order of the jobs to be printed may be different from the order of jobs as scanned, depending on the priority of the jobs and the desires of the operator for increasing productivity or through-put and decreasing printer or scanner down-time.
In such a system, faults can occur on all levels of functioning. Software object faults may occur to result in such problems as illegal job parameters, corrupted data, resource problems, input master errors, font problems, etc. Mechanisms for dealing with such faults are an integral and necessary component of the system, because such faults will result in the interruption of the system, and possibly a crash of the system which requires that the system be rebooted. Information from the system provided to the operator directing the operator to the fault or faults causing the job interruption is critical to the efficient operation of the system.
An important item of information is the nature of the fault which has occurred for the purposes of determining the manner in which cycle-up will take place in the system after recovery from the fault. Certain components of the system have moving parts which could prove unsafe to an operator in close proximity to them while the machine is operating. If the fault has affected such a component, it could be dangerous to an operator to be near the machine if the machine were to cycle up automatically after a fault or a crash.
The related art disclosed in U.S. Pat. No. 4,327,993 to Gauronski, the disclosure of which is herein incorporated by reference, reveals a printing system which provides for a job recovery system for a reproduction machine. The system permits either a manual or an automatic cycle-up procedure depending on the clearance procedures required. Various machine malfunctions require different degrees of operator intervention and job recovery. For example, the system will automatically resume operation after recovery from such faults as the top tray being full, a tray being empty, or the stacker requiring unloading.
While the related art provides for a job recovery system, it fails to disclose a system whereby the system evaluates the potential danger to the operator in the event of an automatic cycle-up after recovery from a fault. It is desirable to devise a system that will cycle-up as soon as possible after a fault or a crash in order to maximize the efficiency of the system. It is equally desirable to insure that the potential for any danger to the operator during cycle-up is minimized.